Solano County Superior Court Judge Robert Bowers declared the mistrial after the jury announced it was deadlocked after just three hours of deliberations. Nine jurors felt Pearsall was guilty of the DUI charge; three felt he was guilty of the hit-and-run charge.

Both charges are misdemeanors with a maximum jail sentence of six months.

Solano County Deputy District Attorney Rashaan Jones said afterward the case will be re-tried. A trial-setting date was scheduled for May 2, in Bowers' Fairfield courtroom.

Pearsall's defense attorney Dan Russo said, "It was a tough case and I'm hoping the district attorney realizes they are never going to get a conviction."

Russo added, "Mr. Pearsall was hoping for vindication. I'm sad because I would like it to be a verdict for him."

The case stems from Pearsall's arrest in July 2012, after he allegedly struck a parked car in a shopping center parking lot and later bumped a police car in front of his house in the 200 block of El Camino Real in Vallejo.

Pearsall, 68, didn't dispute the evidence that he drove while impaired. Instead, he fought the charges based on his belief that he didn't know -- and wasn't properly warned -- about the medication's intoxicating effects.

The defense also presented evidence of Pearsall's reputation for sobriety and community service, including his 36 years as a police officer, his Vallejo City Council term from 2003 to 2007 and his work for the neighborhood revitalization non-profit Fighting Back Partnership.

He retired from the Vallejo Police Department in 2003.

During the three-day trial, police Lt. Herman Robinson, former Solano County prosecutor Doug Keener and former Vallejo Mayor Tony Intintoli testified about Pearsall's reputation and work in the community.

"Sitting with cuffs in the back of the squad car broke his heart," Russo said in closing arguments Thursday.

Jones acknowledged Pearsall's good work in the community, but urged the jury not to give the defendant a "free pass."

"That's not how the law works," Jones said.

Jones argued Pearsall should have known about Ambien's effects because he had been taking it off-and-on for 18 months to help him sleep. Pearsall said the medication was prescribed after neck surgery. He added that the medication's warning label at the time advised patients not to mix the drug with alcohol and to "use care" if operating a car.

The U.S. Food and Drug Administration has since approved label changes warning patients not to drive after taking the medication, including the next morning. Last year, the FDA also approved new dosage recommendations because of the drug's strong effects.

Pearsall -- who's married to former two-term Vallejo City Councilwoman Stephanie Gomes -- was arrested on July 22, 2012. According to police, officers received a complaint at about 9:15 p.m. of a hit-and-run in the parking lot of the former Lucky supermarket at Tuolumne and Redwood streets.

A witness gave officers a description of the suspect's vehicle and a license plate number, which turned out to be Pearsall's, police said.

Officers then drove to Pearsall's residence trying to find the car. As the patrol car turned south on El Camino Real officers saw the vehicle driving on the wrong side of the street at a slow speed, police said at the time.

On Tuesday, Police Officer Megan Sheridan testified that Pearsall appeared to be "confused" and "disoriented" when she approached his car to ask him for his keys.

At some point, Sheridan said Pearsall's car jolted forward and struck the front of the police car, possibly because he had taken his foot off the brake without putting his vehicle in park. She also said Pearsall had trouble keeping his balance when he exited the car, adding that his eyes were bloodshot and his speech was slow and staggered.

On Wednesday, Solano County Criminalist Supervisor Denise Lyons testified that Pearsall tested positive for Ambien and a small amount of alcohol. She said mixing alcohol with Ambien intensifies the effects.

"It causes drowsiness," Lyons said. "You're too tired to stay awake. When you combine that with alcohol I'd expect that to be more intense."

Pearsall told police he had two glasses of wine with dinner before taking Ambien around 8:30 p.m. Although he intended to go to sleep, he said he drove to the supermarket -- which is about a mile from their house -- because his wife asked him to buy her some Benadryl.

After paying for the Benadryl, he said he blacked out.

"The first place I knew where I was was in the back of a police car," Pearsall testified Wednesday.

Pearsall testified he forgot he had taken Ambien before heading to the store.

When he regained consciousness and realized what had happened, he said he was "devastated."

On Wednesday, Gomes testified she'd asked her husband to buy some Benadryl for an allergic reaction she was suffering.

A short time later, Gomes said she heard screaming outside and a women yelling, "Get out of the car." Gomes added she didn't recognize her husband at first when she went outside and later asked officers to take him to the hospital because she thought he needed medical attention.

In a recorded interview with officers, Pearsall said he didn't recall the drive home from the store. The interview, taped at Kaiser Permanente Vallejo Medical Center after Pearsall had been read his rights, was played for the jury on Wednesday.

"I thought maybe I hit something ... but I wasn't sure what it was," he can be heard saying. He added that he thought he'd gone over a curb.

Pearsall told officers he didn't feel impaired when he left for the store.